| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // UNSUPPORTED: c++03, c++11, c++14, c++17 |
| |
| // template<class F, class... Args> |
| // concept equivalence_relation; |
| |
| #include <concepts> |
| |
| struct S1 {}; |
| struct S2 {}; |
| |
| struct R { |
| bool operator()(S1, S1) const; |
| bool operator()(S1, S2) const; |
| bool operator()(S2, S1) const; |
| bool operator()(S2, S2) const; |
| }; |
| |
| // clang-format off |
| template<class F, class T, class U> |
| requires std::relation<F, T, U> |
| constexpr bool check_equivalence_relation_subsumes_relation() { |
| return false; |
| } |
| |
| template<class F, class T, class U> |
| requires std::equivalence_relation<F, T, U> && true |
| constexpr bool check_equivalence_relation_subsumes_relation() { |
| return true; |
| } |
| // clang-format on |
| |
| static_assert(check_equivalence_relation_subsumes_relation<int (*)(int, int), int, int>()); |
| static_assert(check_equivalence_relation_subsumes_relation<int (*)(int, double), int, double>()); |
| static_assert(check_equivalence_relation_subsumes_relation<R, S1, S1>()); |
| static_assert(check_equivalence_relation_subsumes_relation<R, S1, S2>()); |
| |
| // clang-format off |
| template<class F, class T, class U> |
| requires std::relation<F, T, U> && true |
| constexpr bool check_relation_subsumes_equivalence_relation() { |
| return true; |
| } |
| |
| template<class F, class T, class U> |
| requires std::equivalence_relation<F, T, U> |
| constexpr bool check_relation_subsumes_equivalence_relation() { |
| return false; |
| } |
| // clang-format on |
| |
| static_assert(check_relation_subsumes_equivalence_relation<int (*)(int, int), int, int>()); |
| static_assert(check_relation_subsumes_equivalence_relation<int (*)(int, double), int, double>()); |
| static_assert(check_relation_subsumes_equivalence_relation<R, S1, S1>()); |
| static_assert(check_relation_subsumes_equivalence_relation<R, S1, S2>()); |
| |
| // clang-format off |
| template<class F, class T, class U> |
| requires std::equivalence_relation<F, T, T> && std::equivalence_relation<F, U, U> |
| constexpr bool check_equivalence_relation_subsumes_itself() { |
| return false; |
| } |
| |
| template<class F, class T, class U> |
| requires std::equivalence_relation<F, T, U> |
| constexpr bool check_equivalence_relation_subsumes_itself() { |
| return true; |
| } |
| // clang-format on |
| |
| static_assert( |
| check_equivalence_relation_subsumes_itself<int (*)(int, int), int, int>()); |
| static_assert(check_equivalence_relation_subsumes_itself<R, S1, S1>()); |